Stitching machine



STITCHING MACHINE Filed March 25, 1931 5 Sheets-Sheet 1 I N VEN TOR.

1 1 J7- cH J6 $9 I frz/zng H Meicalf 1 BY 2 x A TTORNEY.

April 25, 1933. l. R METCALF 1,906,075

STITCHING MACHINE ATTORNEY April 25, 1933. R METCALF 1,906,075

STITCHING MACHINE A TTORNE Y.

April 25, 1933. R, T L 1,906,075

STITCHING MACHINE Filed March 25, 1951 5 Sheets-Sheet 4 ff .1a

ATTORNEY.

51 INVENTOR.

Patented Apr. 25, 1933 UNITED STATES PATENT 'IOFFICE IRVING R. METGALF, OF ST. CHARLES, ILLINOIS, ASSIGNOB '10 LAM MACHINERY COMPANY, A. CORPORATION 01 ILLINOIS STITCHING MACHINE The present invention is directed nerally to stitchin or staple forming an driving machines, ut more particularly to a novel and improved construction of a narrow head.

One of the objects of the present invention is to provide a novel and improved narrow head stitching mechanism in which an air pressure plunger forms the operatlve connection between the staple former and staple driver to maintain the staple former under yielding air pressure against the work being stitched while the staple is being driv en into the work by the staple driver.

A further object of the invention is to provide an improved stitching mechanism whereby means is provided for ejecting a staple in the event it becomes cau ht on the lower end of the staple driver w ich some times occurs when the stitching mechanism is accidently actuated.

A further object of the invention is to provide a novel and improved narrow head stitching mechanism in which a single manually operable means is provided for simultaneously adjusting the wire feeding means with the wire severin means.

A still further ob ect of the invention is to provide a novel and improved narrow head stitching mechanism in which a novel form of wire grip for feeding the wire to the staple forming and driving mechanism is actuated to feed the wire downwardly on the upward or return stroke of the staple former and driver.

These and other objects are accomplished by providing aconstruction and an arrangement of the various parts in the manner hereinafter described and particularly pointed out in the appended claims.

Referring to the drawings:

Fig. 1 is a front elevational view of my improved stitcher head;

Fig. 2 is a cross sectional view taken on the line 2.2 in Fig. 1;

Fig. 3 is a fragmentary front elevational view with portions of the stitcher head removed showing the positions of the sta 1e former in the process of forming a stap e;

Fig. 4 is a similar view showing the staple forming and driving mechanism in position where the driver is about to drive the staple, into the work;

Fig. 5 is a similar view showing the position of the staple forming and driving mechanism at the completion of driving and clinching of the staple in the work;

Fig. 6 is an enlarged fragmentary front elevational View with portions of the stitcher head removed and certain other portions shown in cross section;

Fig.7 is a cross sectional view taken on the line 77 in Fig. 2;

Fig. 8 is a cross sectional view taken on the line 8-8 in Fig. 2

Fig. 9 is a cross sectional view taken on the line 9-9 in Fig. 2;

Fig. 10 is a cross sectional view taken on the line 10-10 in Fig. 2;

Fig. 11 is a fragmentary cross sectional view showing the manner in which the staple former is locked to the sliding block at the conclusion of the staple driving and clinch ing operation;

Fig. 12 is a cross sectional View taken on the line 1212 in Fig. 11;

Fig. 13 is a fragmentary front elevational view of the upper portion of the stitcher head showing the construction and operating parts of the mechanism for adjusting the wire feeding and wire severing means;

Fig. 14 is an enlarged front elevational view showing the construction of the wire p Fig. 15 is a front elevational view of a fragmentary portion of the cover showing operative parts mounted thereon;

Fig. 16 is a cross sectional View taken on the line 1616 in Fig. 15;

Fig. 17 is a cross sectional view taken on the line 1717 in Fig. 15;

Fig. 18 is a cross sectional view taken on the line 1818 in Fig. 15; and

Fig. 19 is a cross sectional view taken on the line 1919 in Fig. 6.

The present inventlon is an improvement over my joint patent issued to Irving R. Metcalf et al, No. 1,7 62,235, issued June 10, 1930 on wire stitcher head. In the manner described in this patent, the stitcher head herein described is adapted to be mounted on a conventional form of stitching machine in which one or more of these heads may be used for stapling books, pamphlets and the like. For the purpose of illustration I have shown the same as comprising a main frame generally indicated by the reference character 25. This stitcher frame 25 is preferably in the form of an elongated head which is provided on its rear side adjacent its lower end with a transverse recess 26 and an aperture 27 for securely fastening the head to the stitching machine proper in the manner clearly described and illustrated in the aforesaid mentioned patent. The stitcher head 25 is suitably recessed throughout its longitudinal length for the accommodation of the wire stitching mechanism hereinafter described.

Staple forming and drz'mhzg mechanism One of the important features of the pres ent invention has to do with the employment of a novel air cushion construction to take care of the differential motion between the staple forming mechanism and the staple driving mechanism and also for maintaining a yielding pressure on the staple former to hold the work under pressure during the time the staple driver is driving the staples into the work. This feature of the invention also contemplates the locking of the staple former with the staple driver at difi'erent positions of their relative movement with respect to each other and particularly at the moment that the staple driver completes its operation of driving the staple into the work and returning both the staple former and driver simultaneous from contact with the work for a portion of the distance of their return stroke.

This arrangement of locking and unlocking the staple former and driver at different positions in their relative movement with respect to each other also eifects the ejection of a lodged twisted staple which may become caught on the end of the driver on occasions when the stitching mechanism is accidentally tripped.

This novel staple forming and driving mechanism includes a reciprocable slidable block 28 which is mounted in a vertically disposed slot generally indicated by the reference character 29. The block 28 is provided on its opposite sides with laterally extending vertically disposed ribs 39 which engage vertically extending complimentary guide grooves 31 formed in the block 25 as clearly shown in Fig. 9 of the drawings. Secured in a recess 32 located on the rear side of the block 28 by means of a screw 33 is a pitman 34 which has its upper end offset as shown at 35 for engagement with the driving part of the stitching machine in the manner described in the above mentioned patent. The block 28 is provided with a vertically extending cylindrical socket 36 which extends from the bottom of the block to a point adjacent the upper end thereof. This socket forms the air pocket or cushion for a reciprocal cylindrical plunger 37 which is mounted in the socket 36. Located in the axial center of and in the upper end of the plunger 37 is a cylindrical recess 38. Communicating with the cylindrical recess 38 and extending vertically downward in the axial center of the plunger 37 is a reduced bore 39. Formed between the upper end of the bore 39 and the cylindrical socket 38 is a conically shaped valve seat 40. Mounted on the valve seat 40 is a ball valve 41. The ball valve 41 is normally held pressed against the seat 40 by a compression spring 42. The spring 42 and ball 41 are prevented from displacement in the socket 38 by means of a transverse pin 43. Located in the lower rear side of the block 28 is a horizontal aperture 44 in which is reciprocally mounted a locking pin 45. The locking pin 45 is normally actuated inwardly toward the plunger 37 by means of a compression spring 46 which in turn is mounted in a socket formed in the pin 45 with the outer end thereof engaging a fiat supporter spring 47. The supporter spring is secured at its upper end to the block 28 by means of a screw 48. The inner end of the plunger locket pin 45 is adapted to engage a horizontal cylindrical recess 49 formed on the rear side of the plunger 37, when the plunger assumes the position so that the recess 49 reg isters with the aperture 44 in the block 28. The recess 49 also communicates with the cylindrical bore 39 by means of a passage 50 in the pin 45 so that air may be drawn therethrough and pass the ball valve 41 when the plunger 37 is withdrawn from the cylindrical socket 36 formed in the sliding block 28, as is clearly shown in Fig. 2 and Fig. 10 of the drawings. The plunger locking pin 45 is provided with two laterally projecting arms as indicated at 51 which are adapted to engage camming plates secured to the opposite inner sides of the frame 25 in the manner hereinafter described. Positioned below the cylindrical recess 49 in the plunger 37 is a second cylindrical recess 52 which is adapted to receive in engagement therewith, the pin 45 when the staple driver hereinafter described together with the sliding block reaches its lowermost position in the operation of driving and clinching the staple. This last recess 52 permits locking connection between the staple former and driver at a different position in the relative movement of these parts with respect to each other so that these same parts may move up in unison after the conclusion of the operation of forming, driving and clinching the staple. (See F ig. 11.) The lower end of the plunger 37 is provided on its forward side with a recess 53 in which is secured by means of a pin 54 a staple former 55. The staple former is mounted in suitable grooves located in the opposite side frame portions of the main frame 25 in a manner well understood in the art. The sta 1e former consists of two vertically extending legs 56 and 57 on the inner forward edges of which are two vertically extending grooves 58 which form the guideway for the reciprocating driver generally indicated by the reference character 59. (See Figs. 3 and 4.) Mounted in a suitable recess 60 intermediate the ends of the former 55 is a staples supporter 61 which is pivoted on a pin 62 secured to the staple former 55. (See Figs. 2 and 11.) The lower or free ends of the staple supporter 61 is provided with a forwardly curved pointed end as shown at 63 which is adapted to cooperate and extend between the legs 56 and 57 of the staple former 55 for supporting the staple as the same is being driven into the work by the staple driver 59 in the manner well understood in the art. The lower rear end of the staple supporter 61 is provided with a transversely or laterally projecting pin 64 which is adapted to engage the rearwardly and upwardly inclined cammingsurfaces 65 of each of the cam plates 66 secured to the opposite inner sides or side walls of the main frame In a manner well understood in the art. the opposite ends of the pin 64 on the staple supporter 61 engage the inclined caniming surfaces 65 for withdrawing the staple supporter from beneath the staple former and driver on the upward stroke of the staple forming and driving mechanism. After the staple former and driver has been moved upwardly a short distance, the pin 64 engages the rear vertical edges 67 on each of the camming plates 66 so as to maintain the staple supporter out of the path of the staple former and driver during certain portions of the cycle of operation of the stitching mechanism. The upper rear edges of each of the camming plates 66 are provided with downwardly and rearwardly inclined camming surfaces as indicated at 68 which terminates incurved portions as shown at 70. These curved camming portions are connected to forwardly inclined surfaces 68 which finally terminate in vertically extending recesses as shown at 70. The inclined camming surfaces .68 of each of the camming plates 66 are adapted to engage the oppositely projecting arm 51 of the plunger locket pin 45 on the downward stroke of the staple forming and driving mechanism so as to disengage the pin 45 from the upper aperture 49 in the plunger 37. This releases the sliding block 28 from its engagement with the staple former after the former has completed its function of forming the staple, so as to permit the driver to move downwardly relatively of the former in driving the staple into the work. The staple driver 59 is connected to the sliding block 28 throu h the medium of a forwardly projecting lug 1' formed on the lower end of the sliding block 28. This lug engages a recess 72 formed on the upper end of the driver 59. The lower end of the driver 59 is provided with a recess 73 which is adapted to detachably receive a reversible driver end 74, which in turn is detachably secured therein by means of a flat spring 75 having its lower end secured to the driver 59 by means of a rivet 76. The upper free end of the spring is adapted to engage a recess 77 formed on the rear side of the driver end 74. (See Fig. 11.) Secured to the rear side of the former 55 in a recess 7 8 is former slide stop 79 which is adapted to engage stops 80 formed on each of the forward edges of the cam plates 66. This top 79' limits the downward movement of the staple former and driver. The plun er 37 is prevented from displacement in the block 28 by means of a set screw 78' which is provided'with a lug 7 9 which in turn extends into a recess 80 formed on one side of the plunger. (See Fig. 12.)

W ire feeding mechanism Another important feature of the present invention includes a novel feeding mechanism in which the wire is fed downwardly parallel to the travel of the staple former and driver by a wire gripping means which is actuated downwardly during the return or upward movement of the staple former and driver. A

This novel feeding mechanism includes a reciprocable wire gripper plate 81 which is provided with oppositely disposed .and laterall extending vertically guiding ribs 82 whic in turn are seated in complementary and vertically extending guiding recesses 83 formed in the cover plate 84. (See Figs. 15 and 16.) Formed integrally with the plate 81 and extending upwardly with respect thereto is wire feed slide 85. Extending vertically through the wire feed slide 85 is a wire guiding groove 86 through which the wire is fed after it passes through a wire check generally indicated by the reference character 87. The wire check 87 comprises briefly a wire check wheel 88 which is journaled on a pin 89. The pin 89 in turn is mounted in inclined slots 90 formed in the opposite side plates of the wire check casing 87. The wire check wheel 88 is normally pressed upwardly to impinge the wire and prevent it from slipping upwardly by means of a spring which has its coil as shown at 91 embracing a pin 92. The free end of the spring as shown at 93 engages the lower periphery of the check wheel 88 while the other end of the spring as shown at 94 engages the lower surface of a pin 95 secured to the front plate 96. The lower end of the wire groove 86 in the wire slide 85 registers with a vertically extending wire groove 97 formed in the upper portion of the Wire grip plate 81.

The mechanism for gripping the wire and feeding it downwardly on the upward stroke of the staple former and driver is mounted on the wire grip plate 81 and comprises a relatively stationary wire grip member 98 which is mounted in a transverse recess 99 located in the grip plate 81. (See Figs. 14, 15 and 16.) This relatively stationary grip member 98 is secured therein by means of rivets 100. The inner edge of this stationary grip plate 98 is provided with a plurality of laterally downwardly extending teeth 101 which are located adjacentthe path ofthe wire as it travels through the guide groove in the gripping mechanism. Cooperating with the relatively stationary wire gripping member 98 is a relatively movable wire gripping member 102 which is pivoted on a pin 103, which in turn, is secured to the plate 81. Formed on the inner edge and adapted to cooperate with the teeth 101 on the stationary plate 98 are a plurality of arcuately arranged teeth 104. These teeth 104 are arranged slightly eccentric with respect to the axis of the gripping member 102 on the pin 103, so that the lowermost portion of the teeth 104 are at a slightly greater distance of the axial center of the pin 103 than are the upper portion of the teeth 104. \Vhen the movable gripping member 102 is in the position shown in Fig. 14 the wire positioned between these teeth will be gripped preparatory to feeding the wire downwardly by the downward movement of the grip plate 81 simultaneous with the upward movement of the staple former and driver. The movable gripping member 102 is normally actuated to grip wire or move to the position as shown in Fig. 14 by a torsional spring 105 located in a socket 106 formed in the gripper plate 81. The coils of the spring 105 are mounted on a pin 10? which in turn is secured to the plate 81. The free end of the spring extends downwardly as shown at 108 and is adapted toengage an upwardly projecting arm 109 formed integrally with the gripper member 102. The other end of the spring 105 as shown at 110 engages a pin 111 which in turn is secured to the plate 81. The gripping member 102 is actuated to release its hold'on the wire by a trip lever, generally indicated by the reference character 112. The lever 112 is pivoted on a pin 113 which in turn is secured to the grip plate 81. The inner end of this lever 112 is provided with a curved nose as shown at 114 which in turn is adapted to engage an inclined shoulder 115 formed on the gripper member 102. The lever 112 is provided with a straight edge portion as shown at 116 which is arranged angularly with respect to the axis of the pivot 113 of the lever 112 and is adapted to engage a shoulder 117 in the plate 81 formed by the recess 99. In order to release the wire, at the conclusion of the downward stroke of the grip plate 81, the trip lever 112 is provided with laterally extendin portion or pointed end 118 which is adapte to engage an adjustable wire feed trip pin 119 which actuates the lever 112 upwardly or from the full line position shown in Fig. 14 to the dotted line position shown in this same figure. The actuation of this lever 112 about its pivot 113 simultaneously actuates the wire grip member 102 in clock-wise direction (when looking at Fig. 14) about its pivot 103 against the torsonal action of the spring 105 to thereby release the wire between the eccentrically arranged gripping teeth 104 of the member 102-and the cooperating gripping teeth 101 of the stationary gripping member 98. It will be noted that by reason of the position of the pointed nose 114 engaging the inclined shoulder 115 on the gripping member 102 and also the relative pivotal center as indicated respectively at 103 and 113 that the two members 102 and 112 will be locked in a position past their dead center or in the position indicated in the dotted line in Fig. 14.

It will be noted that on the downward stroke of the staple former and driving mechanism, the wire grip plate 81 will be returned upwardly with the gripping members 102 and 98 disengaged from the wire. The specific mechanism for accomplishing the reversal movement of the staple and former with respect to the feeding mechanism will hereinafter be described. At the conclusion of the upward or return movement of the gripping mechanism a relatively stationary trip lug 120 is located in the path of the laterally projecting end 118 of the lever 112 so as to engage said lever and move the same from its dotted line position to its full line position shown in Fig. 14, thereby causing the wire grip member 102 to be actuated by the action of the torsonal spring 105 to again grip the wire between the teeth 104 of the gripping member 102 and the teeth 101 of the stationary gripping member 98 preparatory to feeding the next wire blank for forming the next succeeding staple. The projecting trio lug 120 is formed integrally with a plate 121 which in turn is provided with a vertical slot 122 through the means of which the same may be adj ustab-ly secured by means of screws 123 to the frame 25. This wire trip 120 is not ordinarily intended for adjustment although adjustment is provided so that if it becomes necessary, it may be so adjusted that the movable tripper plate 102 may be allowed wire feeding means is at its extreme upper end of the stroke.

The length of the wire fed to the staple forming and driving mechanism is determined by the position of the trip pin 119 which is adjustable through the medium of to engage the wire when the an adjustablevbar 124 .-to the lower end of which the pin 119 is secured. (See Figs. 1, 15 and 17.) This bar 124 is adjustably mounted in a vertical recess 125 located on I the rear face of the front cover plate 84. The upper end of the bar 124 is provided wlth a rearwardly extending pin 126 which extends through a vertical slot 127 in a rear plate 128 secured to the rear side of the cover plate 84. The pin 126 engages a recess 129 formed on the forward side of an adjustable bar 130. The adjustable bar 130 is slidably mounted in the recess 131 formed in the upper and forward portion of the frame 25. (See-Figs. 7, 8 and 13.) The bar 130 is provided with a threaded bore 132 in which is mounted in threaded engagement therewith a threaded screw 133. Secured to the upper end of the threaded screw 133 is a pinion 134. The pinion 134 meshes with and is operatively driven by a gear 135 which in turn, is secured to a shaft 136 above a peripheral flange 137 formed integrally with the shaft. The shaft 136 is journaled in a vertical bore 138 located in the vertical center of the frame 25.

Attached to the upper end of the frame 25 and covering the gear 135 and the pinion 134 is a cap bracket 139. The cap bracket 139 has formed integrally therewith a curved arm 140 to the upper end of which is attached a wire straightening device (not shown). Secured to the upper end of the shaft 136 above the cap bracket 139 is a manually operable knob 141. This knob 141 is operable for adjusting the length of wire fed to the staple forming and driving mechanism as well as the cutting mechanism in the manner hereinafter described.

Wire cutting mechanism Another essential feature of the present invention is directed to a novel and improved construction of a wire severing means as well as a single manually operable means for simultaneously adjusting the wire severing means together with the wire feeding means. This single manually operable means for adjusting the wire severing and wire feeding mechanism is so arranged to lower the trip which releases the grip on the wire feeding mechanism in conformity with elevating or raising the cutter box so that both legs of the formed staple are lengthened uniformly when it is desired to lengthen the staple, and conversely, this adjustment is reversed when the operator is desirous of shortening the length of the staple.

This wire severing mechanism is mounted in a cutter block 142 which is secured to the vertically adjustable cover 84. Pivoted on a pin 143, secured to the cutter box 142, in the recess 144 formed in said block, is a lever 145. The lever 145 is provided with a downwardly extended arm which has its lower 65 end rounded as shown at 146, for engagement with a recess 147 formed in a reciprocating knife 148. This reciprocatineg knife islocated in a transversely arrang slot or recem 148' located in the cutter block 142. The 1ever 145 is provided with an upwardly and laterally inclined arm 149 which has its outer or free end, as shown at 150, adapted to project into the path of a reciprocating lug 151 of substantially rectangu ar construction. The lug 151 is secured by means of rivets 152 to a reciprocating bar 153 which is adapted to reciprocate in a recess 154 located on one side of the frame 25. The knife 148 is provided with a cutting edge as shown at 155 which is adapted to cooperate with a cutter tube 156 located in a vertical slot 157 formed in the cutter block 142. The cutter tube 156 is secured in the slot 157 by means of a wedge member 156' and a transverse screw 157. The cutter tube 156 is provided with a longitudinal or vertically extending oove 158 through which the wire is fed an out by the cutter 148 at the conclusion of the upward stroke of the staple former and driver in the manner hereinafter described. The lever 145 is actuated to move the knife to the left as viewed in Fig. 6 of the drawings, preparatory to cutting the next wire blank by a push pin 159 which is reciprocally mounted in a transverse bore 160 located in the block 142. One end of this pin 159 is provided with a rounded portion as shown at 161 which is adapted to engage vertically extending arm of the lever 145 while the other end of the pin 159 is provided with a bevel portion as shown at 162. The beveled portion is adapted to protrude into a vertical recess 163 located on one side of the block 142 and be engaged by the lug 151 for actuating the pin 159 to the left as viewed from Fig. 6 for the purpose of returning the knife to its position preparatory to severing the next wire blank. The lug 151 is reciprocated to actuate the lever back and forth on the pin 143 through the medium of a bar 153 which has its upper ends provided with a laterally extending curved projection 164 which is adapted to engage a complimentary projection 165 formed on the front of the forwardly projecting ribs 166 of the slide block 28. From the above description, it will be seen that as the sliding block, which carries the staple former and driver, approaches the upper end of its return stroke, the lug 165 on the block 28 engages the lug 164 on the reciprocating bar 153 and thereby raises the rectangular lug 151 into engagement with the outer free end 150 of the lever 145 so as to actuate the lower end 146 of the lever 145 to the right as viewed in Fig. 6 to sever the wire blank between the knife edge 155 and the cutter tube 156 as clearly shown in Fig. 6. The lug 151 is actuated downwardly into engagement with the beveled end 162 of the pin 159 to return the lever 145 and its cooperating knife 148 preparatory to severing the next wire blank by the lower edge 167 of the laterally projecting lug 165 engaging a shoulder 168 ormed on the bar 153. It will be noted that this action, of moving the cutting edge 155 of the knife 148 to the left of the wire groove 158 in the tube 156, occurs approximately at the conclusion of the downward stroke of the staple former and driver in its complete cycle of operation of forming and driving a staple.

Single manual means for szmultaneoualy adjustz'ng the 'wire cutting and wire feeding meclwm'sm Another essential feature of the present invention contemplates the use of a single manually operable means which simultaneously adjusts the wire severing means with the wire feeding mechanism so that as a greater length of wire is fed downwardly to the staple forming and driving mechanism, the cutting mechanism is raised proportionally to the length of wire fed to the staple anvil so that when the legs of the staple are formed about the anvil, they will be of equal length.

The cutting mechanism, which includes the cutter block 142, with the cutting mechanism mounted therein, is vertically adjustable with the front plate 84 with respect to the main frame 25. This front cover 84 together with the cutter box 142 is detachably secured to the front face of the frame 25 by means of spring clips which are secured to the sides of the frame 25 in any well known manner. These spring clips have inwardly projecting ribs 170 which are adapted to overhang the front surface of the cover plate 84 and return the cover in position on the frame 25.

The cover plate 84 together with the cutting mechanism is vertically adjusted by means of a pin 171 which has a rearwardly projecting square head as shown at 172. (See Figs. 15 and 18.) The head 172 projects through a slot 173 located in the plate 96 and is adapted to engage a recess 174 located at the lower end of an adjustable bar 175. This bar 175 is mounted in a vertical recess 176 located on the forward side of the frame 25 as shown in Fig. 13. The bar 17 5 is provided with a threaded socket as shown at 177 in which is-mounted in threaded engagement therewith, a screw 178. (See Figs. 13, 15, and 18.) Secured to the upper end of the screw 178 in any well known manner is a pinion 179 which is adapted to mesh with and be operably driven by the gear wheel 135. (See Fig. 7.) As it will be seen from Fig. 13, one of the screws 178 is a right hand thread, while the screw 133 is a left hand thread so that upon the manipulation of the thumb screw 141 in one direction it will cause the wire feed trip pin 119 to be adjusted upwardly while the front plate 84 together with the cutting mechanism mounted on the block 142, will be adjusted downwardly in order to shorten the wire blank. If it is desirous of lengthening the wire blank so as to form a longer staple, the knob 141 is turned the reverse direction or in a direction to lower the feed trip pin 119 and simultaneously raise the cutting mechanism or front plate 84 which carries the same.

Driving mechanism for wire feed a vertical recess 181 formed in the rear side of the frame 25. The front face of this rack is provided with a plurality of teeth 182 which is adapted to mesh with a pinion 183 which in turn is journaled on a pin 184 secured to the opposite side walls of the recess 185 formed in the center of the frame 25. The lower end of the rack bar 180 is secured in the recess 186 formed on the upper rear side of the sliding block 28. The pinion 183 is adapted to engage a forwardly positioned and vertically reciprocating rack bar 187 which in turn, is provided with gear teeth 188 which mesh with the teeth of the gear 183. The rack bar 187 is mounted in a vertical slot 189 located in the forward side of the frame 25. Secured to the lower end of the rack bar 187 is a pin 190 which is provided with a forwardly projecting square head 191. This square head 191 is adapted to engage a recess 192 formed on the rear side of the wire feed slide 85 for operatively driving the slide and wire gripping means attached thereto. The shaft 136 and knob 141 is provided with a central vertical bore 136' which communicates with a vertical bore 137' in the frame 25 through which lubricant may be supplied to the working parts within the frame.

From the above description it will be readily seen that as the crank connection 34 is actuated downwardly by the driving mechanism in a manner well understood in the art, the slide block 28 will move downwardly carrying with it the staple forming and driving mechanism. As the sliding block 28 moves downwardly and carries with it the rack bar 180 thereby revolving the pinion 183 in a counter clock-wise direction as viewed in Fig. 2, the rack 187 will move upwardly and carrying with it the gripping mechanism mounted on the grip plate 81. As the grip plate 81 moves upwardly, the wire gripping member 102 as well as the lever 112 will be in their dotted line positions as shown in Fig. 14, and at the conclusion of the upward stroke, the laterally projecting end 118 of the lever 112 will engage the wire feed trip 120 to actuate the lever from the dotted line position, to the full line position shown in Fig. 14. In this position the inwardly projecting portion 114 of the lever 112 will be actuated upwardly past dead center, so that the torsional spring 105 will rotate the wire grip member 102 in a counter clock-wise direction to impinge the wire between the teeth 104 and the teeth 101 of the gripping member 102 and 98 respectively preparatory to feeding the next successive wire blank.

Staple forming an-m'l The construction and operation of the anvil over which the wire blanks are formed into staples by the staple former, is substantially identical with that disclosed in the aforementioned patent and comprises briefly, a U-shaped anvil supporting yoke 193 which has its legs thereof secured in suitable recesses 194 to the lower outside portions of the main frame 25. This yoke 193 is provided with a bearing portion 195 in which an anvil 196 is j ournaled. The inner end of the anvil is provided with a slot for the reception of the wire blank and a gripping means for retaining the wire therein of a construction identical with the construction disclosed in the aforesaid mentioned patent. The anvil 196 is operatively connected so as to cooperate with the staple forming and driving mechanism through the medium of a crank 197 which is preferably made of a fiat piece of spring steel and has its lower ends provided with a pin 198 which is adapted to engage a recess 199 located inthe outer end and eccentrically with respect to the axis of the anvil 196. The upper end of the crank 197 is detachably secured to a pin 200. The pin 200 is secured to a reciprocating bar 201 mounted in a recess 202 located in the front face of the main frame 25.

The anvil is rotated from its wire receiving position to a pos tion in which it holds the blank horizontally preparatory to the downward movement of the staple former. The crank 197 is actuated by a laterally projecting lug 203 formed on the upper and forward face-of the sliding block 28. This lug 203 is adapted to engage a shoulder 204 formed on the reciprocating bar 201. The anvil 196 is normally returned to its wire receiving pos'tion by the lug 203 engaging an inwardly projecting shoulder 205 formed on the upper end of the reciprocating bar 202.

The operation of my improved wire stitching head mechanism is as follows:

Let us assume that the wire feeding means which includes the wire grip carried by the plate 81 is at the upper end of its stroke and that the wire forming and driving means are in their lowermost positions. Upon the upward stroke of the staple forming and driving mechanism, the rack 181 is also moved upwardly, thereby driving the pinion 183 in a clock-wise direction as viewed in Fig. 2 of the drawings. This clock-wise movement of the pinion 183 drives the rack 187 downwardly and through the engagement of the pin 191 engaging the recess 192 in the slide 85, the wire grippin means carrled by the plate 81 is moved ownwardly to feed the wire blank into the anvil 196. As previously pointed out, when the lever 112 engages the trip pin 119, the lever 112 is actuated from its full lined position shown in Fig. 14 to the dotted line position, thereby releasing the grip on the wire. At the conclusion of the wire feeding operation or at the time the staple former and driver approaches the upper end of its stroke, the lug 165 on the sliding block 28 engages the lug 164 of the reciprocating bar 53 causin the projection 151 to engage the outer en 150 of the lever 145 to actuate the knife 148 to sever the wire. Upon the downward movement of the slide block 28 the staple former 55 and driver 59 moves downwardly in unison, but at the time the lower end of the former contacts with the work, the laterally projecting arm 51 of the plunger locking pin .45 engages the bevelled surfaces 68 of the camming plates 66 so as to disengage the locking pin 45 from the upper recess 49 in the plunger 37, thereby permitting the staple driver to proceed on its downward course of driving the staple into the work. By reason of the air pocket or cushion 36 within the block 28 the staple former, through the plunger 37 is yieldingly maintained against the work by air pressure. At the conclusion of the stroke of the driver, it will be noted that the laterally projecting arm 51 of the locking pin 45 move into the recess in the camming plate 66 under the pressure of the spring 46 so as to lock the pin 45 in the lower recess 52 in the plunger 37 so that upon the initial upward movement of the sliding block 28, the staple former and driver are moved together until they are again released by the high portion as indicated at 70 of the camming plate 66. This high portion 7 0' disengages the pin 45 from the lower recess 52 permitting the staple driver to proceed upwardly in advance of the. former until such time as the arms 51 of the pin 45 travel on the inclined surfaces 68 of the camming plates 66, thereby permitting the pin 45 to again become locked in the recess 49 of the plunger 37.

It will be noted that during a portion of the upward movement of the sliding. block 28, especially during the time that the block 28 is moving upwardly with respect to the plunger 37 which occurs during the time which the locking pin 45 is being unlocked and held out of the recesses in the plunger, that the air compressed in the pocket 37 will assist the sliding block 28 to move relatively to the plunger 37, but in order to prevent the possibility of a partial vacuum being created in the pocket 36, the relief valve 41 will permit air to be drawn in to the aperture 44 and 50 in the sliding block 28 and pin 45 respectively and then through the recess 49 which in turn communicates with the vertical bore 39 in the plunger 37. The air will pass through the bore 39 and unseat the ball valve 41 from where it will pass into the pocket or air chamber 36.

It will of course be further noted that by this arrangement of air compression chamber for permitting a relative movement a staple driver with respect to the staple former not only eliminates the use of a spring which has been more or less troublesome in these types of heads that have been used heretofore, but also provides a very efiicient cushion for maintaining the former under yielding pressure against the work while the staple is being driven by the staple driver.

Should the operator desire to lengthen or shorten the staples in accordance with the thickness of the work being worked upon, this may be accomplished by the manipulation of a single manual means which simultaneously adjusts the length of the wire feeding means together with a corresponding adjustment of the wire severing means.

This particular adjustment is accomplished by turning the thumb knob 141 located on the top of the stitcher head, which in turn, through the gear 135 and meshing pinions 134 and 179, the bar 130 is lowered while the bar 175 is raised on account of the right and left hand threaded screws 133 and 178 respectively. If it is desired to shorten the length of the staple, thumb screw 141 is turned in the opposite direction so as to raise the bar 130 and lower the bar 175. In the manner hereinbefore described, the lowering of the bar 130, lowers the pin trip 119 which controls the releasing of the wire grip which feeds the wire downwardly on the upward stroke of the staple former and driver, while the upward movement or adjustment of the bar 175 correspondingly raises the severing mechanism and knife 148 with the front plate 84, so that as a longer wire blank is fed into the anvil the knife is correspondingly raised to make both portions of the wire blank projecting on the opposite sides of the anvil of equal length. It will be readily seen that I have not only provided a simple, compact and efficient narrow head stitcher in which the number of parts is reduced to a minimum, but also one in which elimination of the spring for taking care of the differential movement between the staple forming and driving mechanism and the substitution of an air plunger is made therefor, affording a construction in which no repair is required which is usually occasioned by the use of a spring in this connection with stitcher heads heretofore constructed.

While in the above specification I have described one embodiment which my invention may assume in practice, it will of course, be understood that the same is capable of mod ification and that modification may be employed without departing from the spirit and scope of the invention as expressed in the followin claims:

What claim isany invention and desire to secure by Letters Patent is:

1. A wire stitching mechanism comprising a staple forming mechanism, a staple driving mechanism, and an air cushion mechanism associated with said staple forming and staple driving mechanism for permitting a differential motion between said staple forming and driving mechanism.

2. A wire stitching comprising a staple forming mechanism, a staple driving mechanism associated with said staple forming mechanism and an air cushion associated with said staple forming and driving mechanism for maintaining the former under a yielding pressure against the work during the time the driver is driving the staple into the work.

3. A wire stitcher comprising a staple forming mechanism, a staple driver operatively connected with said staple forming mechanism, and an air pressure means between said staple forming mechanism and said staple driver for cushioning the movement of said staple driver with respect to said staple forming mechanism.

4. A wire stitcher comprising a staple forming mechanism, av staple driving mechanism associated with said staple-forming mechanism, and an air cushioned plunger associated with said staple forming and driving mechanism for permitting a differential movement between said staple forming and driving mechanism.

5. A wire stitcher comprising a frame, a sliding block mounted on said frame, a staple former associated with said block, a staple driver associated with said staple former, and air cushion means operatively connecting said staple former to said block for permitting a differential movement between said staple former and said driver.

6. A wire stitcher comprising a frame, a reciprocable sliding block mounted on said frame, a staple driver connected with said block, a staple former associated with said driver, and means including a reciprocable air cushioned plunger carried by said block and connected to said former for permitting a differential movement between said former and said driver.

7. A wire stitcher comprising a frame, a reciprocable sliding block mounted on said frame, a driver detachably secured to said sliding block, a staple former reciprocally mounted on said frame and associated with said driver, there being a cylindrical air pocket formed in said block, and a reciprocable air plunger mounted in said pocket and connected with said former for permitting a differential movement between said former and said driver.

8. A wire stitcher comprising a frame, a reciprocable sliding block mounted on said frame, a former associated with said block and reciprocally mounted in said frame, a

driver reciprocally mounted in said former and connected to said block, there being a vertically disposed cylindrical air pocket formed in said block, and an air plunger reciprocally mounted in said pocket and connected to said former for yieldingly maintaining said former under air pressure against the work during the time said driver is driving the staple into the work.

9. A wire stitcher comprising a frame, a vertically reciprocable sliding block mounted on said frame, a vertically reciprocable staple former mounted on said frame and associated with said block, a vertically reciprocable driver mounted in said former and connected to said block, and an air pressure mechanism forming the connection between said block and said former for permitting a differential motion between said staple former and driver.

10. A wire stitching mechanism comprising a frame, a reciprocally actuated sliding block mounted on said frame, a staple former reciprocally mounted on said frame and associated with said block, a staple driver mounted in said former and detachably connected to said block, there being a vertically disposed air pocket located in said block, a plunger reciprocally mounted in said pocket and having one end thereof connected to said former, and an inlet valve carried by said plunger whereby the air may be drawn into saidpocket for forming a cushion so as to permit a differential movement between said staple former and driver.

11. A wire stitcher comprising a staple forming mechanism, a staple drivin mechanism associated with said staple orming mechanism, means for driving said staple forming and driving mechanism, means for permitting a differential movement between said staple formingapd driving mechanism, and means for loc g said staple forming and driving mechanism together in more than one position of their relative movement.

12. A wire stitcher comprising a staple former, a staple driving mechanism associated with said staple former, means for permitting a differential movement between said staple former and driver, and means including a pin for locking said staple former and driver in more positions than one during their relative movement with respect to each other.

13. A wire stitcher comprising a frame, a reciprocable staple former mounted on said frame, a reciprocable staple driver associated with said staple former, means for driving said staple former and driver, means for permitting a relative movement of said driver with respect to said former, and means for lockin said staple former and driver together at 51c conclusion of the downward stroke of the staple driver.

' 14. A wire stitcher comprising a frame, a reciprocable staple former mounted on said frame, a reciprocable staple driver mounted in said staple former, means for permitting a differential movement between said sta le former and driver, means for locking sai staple former and driver together in various positions of their relative movement with respect to each other, and means carried by said frame and engageable with said last named means for unlocking said staple former from said driver.

15. A wire stitcher comprising a frame, a reciprocable sliding block mounted on said frame, a staple former mounted on said frame, a staple driver reciprocally mounted on said former and connected to said block, there being a cylindrical recess formed in said block, an air plunger mounted in said cylindrical recess and connected to said staple former for permitting a differential movement ''between said staple former and said staple driver, and means carried by said block and engageable with said plunger for locking said former and driver together in more positions than one in their movement with respect to each other.

16. A wire stitcher comprising a frame, a reciprocable sliding block mounted on said frame, a staple former associated with said block and reciprocably mounted on said frame, a staple driver reciprocably mounted on said former and connected to said block, there being a cylindrical air pocket formed in said block, a reciprocable plunger mounted in said pocket and having one end thereof connected to said staple former, there being a plurality of vertically spaced apart recesses formed in said plunger, and a spring actuated pin carried by said block and adapted to engage the recesses in said plunger for locking said staple former to said staple driver in various positions of their movement with respect to each other.

17. A wire stitcher comprising a frame, a reciprocable sliding block mounted on said frame, a reciprocable staple former mounted on said frame and associated with said block, a staple driver reciprocally mounted on said former and connected to said block, there being a vertically disposed cylindrical air pocket formed in said block, a reciprocable plunger mounted in said pocket and having one end thereof connected to said former, there being a plurality of vertically spaced apart recesses formed in said plunger, a reciprocable spring pressed pin carried by said block and adapted to engage the recesses formed in said plunger, and means carried by said frame and engageable with said pm for unlocking said pin from said plunger for permitting said driver to have a dlfi'erential motion with respect to sa d former.

18. A wire stitching machine comprlslng a frame, a reciprocable sliding block mounted on said frame, a staple former reel rocally mounted on said frame and operatlve y related to said block, a staple driver reciprocally mounted in said staple former and connected to said block, there being an air cushlon pocket formed in said block, a reciprocable plunger mounted in said pocket and connected to said staple former, means carried by said block and engageable with said plunger for locking said staple former and driver in various positions of their relative movement with respect to each other, and means carried by said frame and engageable with said last named means for controlling the I movement of said staple driver with respect to said staple driver with respect to said staple former.

19. A wire stitching machine comprising a frame, a reciprocable sliding block mounted on said frame, a reciprocable staple former mounted on said frame and operatively related to said block, a staple driver reciprocally mounted on said frame and connected to said block, means for feeding the wire downwardly to said staple former and driver on the upward movement of said sliding block including a rack secured to said block, a gear mounted on said frame and meshing with said rack,

- a second rack mounted on said frame and meshing with said gear, and a reciprocable wire ip feeding means connected to said second named rack for feeding the wire downwardly on the upward stroke of said staple former and driver.

20. A wire stitcher comprising a frame, a reciprocable staple forming and driving mechanism mounted on said frame, a vertically reciprocable wire feeding mechanism mounted on said frame, including a wire gripping means for gripping the wire and feeding the same downwardly on the upward stroke of said staple former and driver, said wire gripping means being actuated by said staple former and driver and means for operatively connecting and driving said wire feeding means by said staple forming and driving means.

21. A wire stitcher comprising a frame, a reciprocable staple forming and driving mechanism mounted on said frame, a reciprocable wire feeding mechanism mounted on said frame including a wire grip which engages the wire at the conclusion of the downward stroke of the staple forming and driving mechanism and feeds the wire downwardly on the upward stroke of the staple former and driver mechanism, and means mounted on said frame and engageable with said wire grip for releasing the grip on the wire at the conclusion of t e upward stroke of said staple forming and dnving mechanism.

22. A wire stitcher comprising a frame, reciprocable staple forming and driving mechanism mounted on said frame, reciprocable wire feeding means for feeding the wire parallel to the direction of drive and downwardly on the upward stroke of the staple former and driver, said wire feeding means including a pivoted wire gripping member having eccentrically arranged teeth adapted to engage the wire, a pivoted lever carried by said wire feeding means and engageable with said wire grip member to actuate the same, and adjustable means mounted on said frame and engageable with said lever for controlling the length of wire fed to said staple forming and driving means.

23. A wire stitching machine comprising a frame, a reciprocable staple forming and driving mechanism mounted on said frame, a reciprocable wire feeding mechanism for feeding the wire downwardly and parallel to the direction of drive during the upward stroke of said staple forming and driving mechanism, said wire feeding means including a reciprocable slide through which the wire passes, a relatively stationary wire grip-- ping member secured to said slide and havmg teeth on one end thereof adapted to engage the wire, a relatively movable wire gripping member adapted to cooperate with said stationary wire gripping member, and a lever pivoted to said slide and engageable with said moveable wire gripping member for controlling the length of wire fed to said staple forming and driving mechanism.

24. A wire stitchlng machine comprising a frame, a reciprocable staple forming and driving mechanism mounted on said frame, a reciprocable wire feeding mechanism adapted to feed the wire parallel to the direction of drive on the upward stroke of said staple forming and drivin mechanism, said wire feeding mechanism including a reciprocable slide through which the wire is fed, a relatively fixed wire grip member carried by said slide having a plurality of teeth on one edge thereof for engagement with the wire to be fed, a pivoted wire grip member carried by said slide and having a plurality of eccentrically arranged teeth adapted to cooperate with the teeth on said relatively fixed member for gripping the wire therebetween, a spring carried by said slide for urging said pivoted wire gripping member to grip the wire between said wire gripping members, a lever pivoted to said slide and engageable with said pivoted wire gripping member for releasing the grip on said wire at substantially the conclusion of the downward stroke of said wire means, and an adjustable trip carried by said frame and engageable with single manually operable means 'for simultaneously adjusting said wire feeding'means and'said severing means. for varymg'the length of wire blanks fed to said staple 0 ing and driving mechanism, I g a 26. A wire stitching achine comprising a frame, a reciprocable,staple forming and; driving mechanism mounted on sa-id frame, wire feeding mechanism for feeding the wire downwardly parallel to and at a position forwardly of the staple forming and. drivin mechanism on the upward stroke of sai slaple forming and. driving' mechanism, a vertically adjustable wire severing means mounted on said frame for severing the wire at the conclusion of the wire feeding operation, and an adjustable trip mounted onsaid frame and operatively related rte-said wire feeding mechanism for releasing the grip on v the wire being fed, and single manually op erable means for simultaneously, raising said cutting mechanism and lowering said trip for increasing the length of the staple formed and drivenby said staple forming and driving mechanism.

27. A wire stitching machine comprising ly operable means for simultaneously adjusting said cutting mechanism in conformity with said wire feeding mechanism so that the length of the legs of the staple being driven by said sta 1e forming and driving mechanism are uni orm.

28. A wire stitching machine comprisin a frame, a'reciprocable staple forming and driving mechanism mounted on said frame, an air pressure plunger operatively connect- .ing'said staple former with said staple driver for permitting differential movement. between said staple former and driver, a reciprocable wire feeding mechanism carried by said frame for feeding the wire parallel to the direction of drive on the upward stroke of. said staple forming and driving mechanism, gripping means carried by said feeding mechanism for gripping the wire at substantially the conclusion of the downward stroke of said stapleforming and driving mecha- Iiism and to release the wire at substantially the conclusion of the upward stroke of said stapleforming and driving mechanism, an

adjustable cutting mechanism for severing the wire at the conclusion of the wire feeding operation, and single manually operable means'for simultaneously adjusting the said wire'feedlng means and said severing means "for varying the length of the blanks fed to said staple forming and driving mechanism. "In testimony whereof I have signed my name to" this specification on this 23rd day of March, A. D. 1931.

' IRVING R. METCALF.

a frame, a reciprocable-staple forming and 7 driving mechanism mounted on said frame, wire feeding mechanism for feeding the wire parallel to and in the direction of drive on the upward stroke of said staple forming and drivin mechanism, means for driving said wire ceding mechanism through said saple forming and drivingmechanism, said wire feeding mechanism'including a reciprocable slide, wiregripping means mountedon said slide including a relatively fixed wire gripping member having a plurality of teeth v on one edge thereof and located ad'acent the path of travelof the. wire being ed therethrough, a movable wire gripping member .carriedby said slide and adapted to coo'perate with said" stationary wire gripping memher for gripping the wire atfsubstantially the conclusion of the downward stroke of the staple forming and driving mechanism and to release the wire at substantially the conclusion of the upward stroke'of the staple forming and driving mechanism, a cover mounted on said frame, a severing means mounted on said cover, and asingle manual- 

